Huck. I own several with the 175 being my most often used. It really depends on what size rivets you using most often. The 175 will do up to quarter inch. I believe you can find them for a liitle north of $200 but well worth the price if you will use it often.
These are what I used. I have pretty much the same set up as you. 80 gallon compressor in the basement ran 3/4 inch copper off the compressor 3/4 inch hose in conduit out to the shop burried in 2 inch conduit 100 feet. Then 3/4 in copper around the top of the shop with 1/2 inch drops dow to...